1. Field of the Invention
The present invention relates to a communication system, and in particular to a computer telephony interface (CTI) for use in such a system.
2. Related Art
A computer telephony interface is a control interface used on a computer which implements or controls one or more nodes in a communications network, For example, Microsoft""s TAPI (telephony application programmer""s interface) might be used in conjunction with a program such as NetMeeting (TRADEMARK) to control a PC used for audio/visual communication with other PCs connected, e.g., to an Intranet. Such a control interface is known as a xe2x80x9cfirst party call componentxe2x80x9d since it models and controls a call from the point of view of one of the parties involved in a connection. Alternatively, a call may be modelled and controlled from a platform which is not either an originating or a destination node in the call. For example, calls using the H323 protocol may be made via a computer platform which is dedicated to a call switching function and which is termed a xe2x80x9cvirtual switchxe2x80x9d (sometimes also termed a xe2x80x9cgatekeeperxe2x80x9d). Such a virtual switch may have a control interface constructed using, for example the Java telephony application programmers interface (JTAPI). This is an example of a third party call component, since the control of the call is based on a view of the call which is not that of either the originating or the destination party.
According to a first aspect of the present invention there is provided a computer telephony interface (CTI) including concurrent first party call components and third party call components.
The invention provides for the first time a control interface which uses concurrently both first party call components and third party call components. Conventional PBX and public networks have been controlled from either the first or third party. However since network functionality is distributed across many components, the ability given by the present invention to control more than one node or switch makes possible control and use of the full functionality of a computer implemented/computer-controlled communications network.
According to a second aspect of the present invention there is provided a computer telephony interface including a plurality of concurrent call components for a plurality of different respective network nodes active in a call.
Preferably the plurality of concurrent call components include first party call components and third party call components.
Preferably one of the said call components is arranged to control a network resource operating a multi-call communications protocol.
The limitations of conventional computer telephony interfaces are particularly marked when used to control devices implementing a multi-call protocol. A multi-call protocol is one which allows a respective network node to engage in more than one call at a time. An example of such a multi-call protocol is H.323 used in Microsoft""s Net Meeting and in other audio/visual conferencing applications.
Preferably the different call components are sub-classes of a single call component parent class.
According to another aspect of the invention, there is provided a telephony server for connection in a telecommunication system and including a computer telephony interface according to any one of the preceding aspects.
According to a further aspect of the invention there is provided a communications system including a computer controlling a plurality of different network resources, in which the computer includes a computer telephony interface in accordance with any one of the preceding aspects of the invention.
According to another aspect of the present invention, there is provided a method of operating a computing system connected to a communications network, the method comprising:
a) selecting one or more of a plurality of call components comprising both first party call components and third party call components;
b) incorporating the or each selected call component in a call model running on the computing system
c) controlling via the said call model network resources corresponding to the or each selected call component, and thereby establishing a call in the said communications network.
The invention also encompasses methods of operating a network, or operating network nodes, using the computer telephony interface of the previous aspects.